Siren



FIG. 1 is a front elevational view of a siren showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a cross sectional view thereof, taken along line 6--6 of FIG. 1;

FIG. 7 is a perspective view thereof. 

The ornamental design for a siren, as shown. 